Bucky Barnes

After losing his father at a young age during World War II, James Buchanan Barnes was adopted as the mascot for Camp Lehigh and nicknamed "Bucky". Because of his skills Bucky was sent to England on his sixteenth birthday, where he went through two months of combat training with the British S.A.S. and another month of special training back in the United States. To his superiors Bucky was the best natural fighter they had ever seen. It wasn't long before he was made Captain America's partner, who unlike Cap could get his hands dirty doing the little tricks that Cap wasn't allowed to do because of regular military methods.

The press then came up with a cover story: "Camp kid becomes Cap's sidekick," which made kids all over the country think it could happen to them too. He soon joined Cap as a member of the Invaders, fighting alongside such other heroes as Namor the Sub-Mariner, Jim Hammond the Human Torch and Thomas Raymond the Toro. As they were about the same age, Bucky and Toro would become close friends, along with the Human Top and Golden Girl, who dubbed themselves "The Kid Commandos". During this time he teamed up with other sidekicks to form the Young Allies and later the Liberty Legion to help the Invaders in their fight against the Red Skull. Bucky also teamed-up with a group of teenage superheroes called the Kid Commandos.

In the closing days of World War II, during a mission overseas to take down Baron Heinrich Zemo, Cap and Bucky hopped on a plane carrying a bomb and hoping to disarm it. Cap couldn't reach it but Bucky hung on. It was booby trapped and the bomb detonated. Bucky found himself too close to the explosion which sent him and Captain America falling into the waters below. While Captain America's body was frozen in a state of suspended animation for years, Bucky's body was never found... Or was it?

Creation

Joe Simon and Jack Kirby created Bucky Barnes as a sidekick for Captain America, named after a childhood friend of Joe Simon's. He first appeared in Captain America Comics #1 in March 1941.

Character Evolution

Bucky has been through some drastic changes in his career.
Major Stories:
The Winter Soldier
The New Captain America
A New Avenger
Captain America: Reborn
Siege
Enter the Heroic Age
No Escape
Trial of Captain America
Captain America and Bucky
The Longest Winter
Broken Arrow
Widow Hunt

Powers, Abilities and Equipment

Bucky is not like Steve, he did not take a Super Soldier Serum, though Bucky is classified as peak human.

Bucky Barnes also has a left Cybernetic Arm that has a significant amount of strength (capable of throwing a shield through guns and steel super computers), it is also capable of producing EMP's and electrical shocks.

Fighting Ability
As a young teenager, James was observed to have remarkable fighting prowess by fighting military men twice his size and age. Concerned, the U.S. Army decided to make use of James fighting ability and immediately sent him off to train with the British SAS. Upon returning, he continued his training under William Essart Fairbairn and Colonel Rex Applegate to become Bucky, the sidekick to Captain America (Steve Rogers).

As Bucky, he was further trained by Steve Rogers until his death and rebirth into the Russian assassin known as the Winter Soldier.

With no prior memory of his former self except for his fighting ability, the Winter Soldier continued to train under the Russians to harness his skill in martial arts and assassinations. Because of his skill, James became the basis for the Red Room program and trained dozens of other Russian assassins including the Black Widow.

Bucky has proven his fighting ability against creditable fighters such as Black Widow, Sin, Crossbones, Batroc the Leaper, Wolverine and more. Although he has doubted himself by comparing his physical ability to Steve's super soldier abilities (Approximately 3 times stronger and faster than himself), with his lack of super soldier formula and ability to go toe to toe against many of Steve’s rouges and win proves that he is on a level close to Steve's fighting ability.

Personality
Bucky, like many others, looks up to Steve Rogers. He has a great deal of respect for Steve, but Bucky is also ashamed of what he has done as Winter Soldier. Bucky has shown signs of aggression whilst depressed and has also redeveloped a relationship with Black Widow.

Equipment
As the Winter Soldier, James's missing arm was replaced by a cybernetic enhancement. As his career progressed as Captain America, Nick Fury found it necessary to upgrade his arm to be fully synthetic in order to look and feel real.

The arm is capable of the following:

When detached, can be controlled by James through mental implants.
Capable of punching through metal and throwing a shield fast enough to slice through human limbs, control panels and assault rifles.
Capable of emitting a electrical shocks.
Capable of emitting an EMP to shut down electrical hardware.
Capable of bypassing any airport sensor.
Holographic imaging to appear as a normal human arm. Looks and feels like a human arm.

Source:http://www.comicvine.com/bucky-barnes/4005-40470/